Anything from 8mm-100mm is useful underwater, it is even possible to fit zoom lenses with gears to zoom in and out if required. I use the following lenses and when I checked through my recent photos I used all of them equally. I use 3 lenses – 15mm Sigma Fisheye, 100mm Canon Macro and a 16-35mm fixed to 24mm. When I was only using natural light the lens I used almost exclusively was the fisheye.
Fisheye Lens: The fisheye is fantastic for wrecks and landscapes, the combination of this lens’ ability to focus close-up and deep depth of field helps to reduce the distance between you and your subject. This reduces the water column between the camera and subject resulting in clearer, sharper photos.
Macro Lens: For a full frame camera, a 1:1 macro like the 100mm is superb for really getting into the detail. Combined with twin strobes you should be able to get fantastic photos with excellent colour and clarity. For a cropped sensor camera a 60mm would do the job just as well. The 100mm also can be used as a fixed zoom to get close to some of the more timid animals or even to capture the face of a fish before if swims off as you approach.
24mm Lens: The 16-35mm fixed at 24mm lens is a new addition to my arsenal and I absolutely love using it. I do not own a 24mm prime and 24mm is as wide as I can go without cropping causes by the ports I own. What is best about using a 24mm focal length is that I found when I am capturing a subject with it they are exactly as I see it with my eyes. This means 90%+ of photos from this do not need any cropping resulting in maximum resolution and the ability to print LARGE! The exception to this is when I need to use it as a macro lens on a dive - as there is no option to swap lenses underwater so you might as well capture it anyway and crop later!
Capturing The Image
It is time to bring it all together and press the shutter button. Load memory card, batteries, choose lens, strobes and port, assemble case and make sure all cables are inside the case. I can vouch for the fact that leaving a cable hanging out of the case will flood your camera and ruin it within seconds! I have a rule about camera assembly – I always do it the night before, not when I am rushing and drowsy in the morning! Using the SLR underwater is much like using it on land apart from your camera weighs in at 7kg and you only have a tripod made of water.
I look through the viewfinder to compose my shot as I would do on land. This takes some getting used to and there are magnifiers available to make this easier. Some of the magnifiers are also angled to make it easier to get low down shots but I find, now that I know my setup, in this situation I can aim the camera in the correct direction and then review immediately underwater. I have never needed to use a magnifier and as they come in at £1000 ish I think I’ll skip them (for now).
I find liveview way too slow to capture anything including coral underwater. I am using central spot focusing but I do move the spot around for composition at times, although this takes a little longer and a patient subject.
To get the most of the images from underwater I find post-processing to be an essential component and here I cover the essentials that are needed to be done rather than an in depth guide on how to do them. To get the most about of the images we need to ensure that photos have been captured in RAW! We will not be using any of that JPEG nonsense here! We are using a calibrated screen as it's essential for all post-processing and this is no different for underwater photography.
During post-processing I apply white balance, black and white adjustments, contrast curve adjustment, shadow recovery and sharpening to all of my photos. Cropping is also done here to compensate for my position in the water as necessary. For these changes and photo cataloguing I use Lightroom. I have been using this since version 1.0 and know my way around it very well. As a final step if there is a lot of backscatter on an image I like I will bring it into Photoshop and apply layers with "Dust & Scratches” filters to the required areas. Good knowledge of whichever software you use is essential to get the most out of your images.
I want to be able to share this magnificent environment with the rest of the planet and I believe to do it the justice it deserves and share its beauty I must strive to ensure my photos are of the best standard and quality I can manage, each and every time. I'll leave you with a couple of my favourite images.